import java.util.Scanner;

public class Example09 {
    public static void main(String[] args) {
//    int grade =75;
        Scanner scl=new Scanner(System.in);
        int grade= scl.nextInt();
    if (grade>80){
        System.out.println("该成绩的等级为优");
    }else if(grade>70){
        System.out.println("该成绩的等级为良");
    }else if( grade>60){
        System.out.println("该成绩的等级为中");
    }else{
        System.out.println("该成绩的等级为差");
      }
    }
}
